Struggle for Life

Struggle for Life

in biology, a metaphorical expression proposed by C. Darwin (1859) to describe an organism’s activity directed at preserving life and providing for the existence of offspring.

The concept of the struggle for life is closely related to natural selection. In the most general sense, the struggle for life derives from the disparity between the great capacity of organisms to multiply and the limited amounts of space, food, water, and so forth necessary for the normal existence of organisms of any species. Thus, according to the calculations of Darwin, under the condition that all offspring survived and bred, a pair of elephants, one of the most slowly multiplying mammals, in 750 years would leave 19 million offspring. One diatom, with unrestricted multiplication, in 36 hours could cover the entire surface of the earth with a film.

However, this potential capacity for multiplication is never fully realized in nature. The majority of the individuals that appear do not survive to adulthood and die in the process of direct or indirect struggle for life—that is, die under the effect of unfavorable climatic or other abiotic environmental factors (constitutional struggle for life), in the struggle with representatives of other species (interspecific struggle for life), or in a struggle with others of its own species (intraspecific struggle for life). Constitutional and interspecific struggle for life, in and of themselves, are only eliminating factors. Only the intraspecific struggle leads to the creation of new forms of organization. Among the factors which result from the competition of different individuals of the given species in the struggle for life and multiplication are selective elimination; general, or random, elimination; individual elimination (which includes the direct elimination by physical factors and biological factors as well as indirect elimination by physiological factors, which leads to the survival of the fitter individuals); and family and group elimination. The combination of individual and group elimination is of particular significance in evolution. Elimination assumes a selective character only through competition, which can be intragroup (active and passive individual), interfamily, and intergroup (I. I. Shmal’gauzen).

Intraspecific struggle for life is manifested in the competition between individuals of a given species when they encounter any enemies or harmful influences, in the competition for food and other vitally necessary factors such as water and light, and in the competition for the more effective protection of their life and offspring. Interspecific struggle for life can occur directly between the predator and the victim as well as between the individuals of different, often very distant, species. For example, herbivorous mammals and herbivorous insects (for example, locusts and crickets) compete or “struggle” for food.

In Darwin’s definition, the concept of the struggle for life included all forms of relationships between organisms and not just the competitive relations of struggle in the narrow sense of the word. Since Darwin’s time, greater emphasis has been put on the biotic conditions (that is, the vital activities of other forms of life with which the given organism is tied by food and any other relations) than on the abiotic conditions for preserving life and leaving offspring.

In vulgarizing the struggle for existence in nature and in arbitrarily transferring its patterns to social life, certain bourgeois sociologists and economists have proposed the concept of social Darwinism. This was sharply criticized by F. Engels (see Anti-Dühring, 1966, pp. 64–66). The methodological error of the social Darwinists was in the attempt to reduce social patterns to the level of biological ones. In following B. Franklin and C. Linnaeus and showing the existence of a drive to multiply in a geometric progression in nature, Darwin in fact rejected the basic idea of the English economist T. R. Malthus on the supposedly existing discrepancy between the multiplication of man (in a geometric progression) and the means of existence (in an arithmetical progression). This notion was particularly taken up by K. Marx (see K. Marx and F. Engels, Soch., 2nd ed., vol. 26, part 2, p. 127).

The concept of the struggle for life, as advanced by Darwin, was of major significance, reflecting the internal moving force of evolution on the level of natural sciences in the 19th century and serving as one of the most important initial premises for Darwin in creating the theory of development of the organic world. In comparing the presence of the struggle for life in nature with the observed diversity of individuals within any species, Darwin concluded that natural selection is the basic moving factor in the evolutionary process. In this manner the theory of evolution was put on a materialistic natural historical basis.

In remaining a broad general concept, the struggle for life, in applied studies, has been broken down into a number of phenomena related to studying the biogeocenotic relationships on the level of populations, species, biocenoses, relations between organisms and abiotic environmental factors, and so forth. In all instances, the struggle for life leads to a comparative evaluation of the individuals in a certain population under the conditions of a specific biogeocenosis, as well as to selective elimination and natural selection.

Bears on natural selection -- The term used in a wide sense -- Geometrical powers of increase -- Rapid increase of naturalised animals and plants -- Nature of the checks to increase -- Competition universal -- Effects of climate -- Protection from the number of individuals -- Complex relations of all animals and plants throughout nature -- Struggle for life most severe between individuals and varieties of the same species; often severe between species of the same genus -- The relation of organism to organism the most important of all relations.

All these results, as we shall more fully see in the next chapter, follow inevitably from the struggle for life.

Nothing is easier than to admit in words the truth of the universal struggle for life, or more difficult--at least I have found it so--than constantly to bear this conclusion in mind.

But a plant on the edge of a desert is said to struggle for life against the drought, though more properly it should be said to be dependent on the moisture.

When we reach the Arctic regions, or snow-capped summits, or absolute deserts, the struggle for life is almost exclusively with the elements.

When a species, owing to highly favourable circumstances, increases inordinately in numbers in a small tract, epidemics--at least, this seems generally to occur with our game animals--often ensue: and here we have a limiting check independent of the struggle for life.

All that we can do, is to keep steadily in mind that each organic being is striving to increase at a geometrical ratio; that each at some period of its life, during some season of the year, during each generation or at intervals, has to struggle for life, and to suffer great destruction.

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